1. Field of the Invention
This invention relates to accumulator apparatus for printed circuit boards and, more particularly, to accumulator apparatus for printed circuit boards having an endless belt with paddles secured to the belt and extending outwardly for receiving and transporting printed circuit boards.
2. Description of the Prior Art
Prior art printed circuit board accumulators generally include free-standing units with an endless belt for moving the circuit boards generally horizontally. Paddles secured to the belt are spaced apart for receiving and holding the printed circuit boards as the belt moves. The paddles are generally individually secured, as by screws, rivets, etc., to the belt.
The accumulators may be used as either feeder elements or collector elements for processing circuit boards, or for a delay in the processing of the boards. An accumulator may receive the printed circuit boards and transport them for storage or for feeding onto a conveyor, to a stacker, etc. The boards, when the apparatus is used as a feeder, may be placed manually on the conveyor belt, and the printed circuit boards may be discharged from the accumulator onto a conveyor of some type. Since an accumulator belt is motor driven, the motor may typically be operable at a speed corresponding to the conveyor system with which the accumulator is matched.
As a collector, the accumulator may automatically receive printed circuit boards from a conveyor by having the circuit boards fed into the space between adjacent paddles and the boards may then be manually removed from the accumulator. Again, the motor operating the apparatus, or causing the belt to move, may be set in accordance with the parameters of the mating equipment. A proximity switch and/or a photo sensor may be used to start and to stop the motor.
One of the inherent problems of the prior art is the means of securing the paddles to a belt. When paddles are riveted to the belt, time is expended in the individual operations required for riveting each paddle. In addition, the cost of the apparatus increases in accordance with the complexity of the assembly and manufacturing process. With either rivets or screws or the like, a substantial amount of hand work is involved which increases the time and expense involved in manufacturing the apparatus.
With the apparatus of the present invention, slots in the paddle receive the timing belt so that a direct securement by means of a mechanical element, such as a screw or a rivet, is obviated. the assembly time, and the corresponding cost of the apparatus, is substantially reduced.